Abstract Thecancerepigenomeismarkedlyaberrant,andchromatinfactorsarecommonlymutatedinmany malignancies.Recentfunctionalstudiessuggestthatchromatinmis-regulationcanpromotede-differentiation andself-renewalofcancercells.However,theepigeneticmechanismsbywhichcancercellfateprogramsare impairedarepoorlyunderstood.Here,Iaimtoaddressthisquestionintwocancersthatareclearlydrivenby chromatinmis-regulation:acutemyeloidleukemia(AML)andpediatrichighgradegliomas(HGGs)suchas diffuseintrinsicpontineglioma(DIPG).AMLdrivermutationscommonlyinvolvetranslocationsofchromatin regulatorygenes,andDIPGdrivermutationsoccurinhistoneH3in80%ofcases.BothAMLandHGGsarise inpoorly-differentiatedcells,andIhypothesizethatchromatinfactorshelpsustaintheseimproper differentiationprograms.?Differentiationtherapy?aimstotreatsuchcancersbyinducingcellularmaturationto disableself-renewalandhaltproliferation.Whiledifferentiationtherapyhasonlybeenusedinthe promyelocyticsubtypeofAML(APL),mypreliminarydatasuggestthatthisapproachmaybesuccessfulin non-APLAMLsandHGGsifthecriticalepigeneticprogramsregulatingcellfatecanbeidentifiedand manipulated.Indeed,wehavealreadyobtainedleadsonpromisingsmallmoleculeinhibitorsandgenetic targetsthatpromotedifferentiation.Inthisproposal,Iwilltakesimilarstrategiestointerrogatetheepigenetic basisofAMLandHGGcancercellfate.Myapproachwillinvolve(1)Integrativeepigenomicprofilingof induceddifferentiationprogramsingenetically-definedorpatient-derivedcancercelllinemodelswithrelevant driverstoidentifya?roadmap?tocancercelldifferentiation,(2)HighthroughputCRISPR-Cas9-based screeningofthesecellularmodelstoidentifychromatinfactorsthatregulatedifferentiation,(3)Biochemical analysestoidentifythemolecularmechanismsbywhichexistingscreenhitsandthosefoundinfuturescreens manipulatechromatintoinfluencecancercellfate,and(4)Validationoffindingsinpre-clinicalanimalmodels andinclinicalsampleanalyses.WhileIwillleadallaspectsofthisinvestigation,Iwillhavedirectsupportfrom severalworldauthoritiesinAMLandHGG.Ultimately,thegoalofthisprojectistoidentifynoveltherapeutic targetsandapproachesforAMLandHGG.Inthefuture,myaimisforthisworktoopenthedoortothe generalizableconceptofusingepigeneticmanipulationtotherapeuticallytargetcancercellidentityprograms.